So-called communication apparatuses such as servers and network equipment include a board with which a communication module is connected. Such a board is generally referred to as a “motherboard” or a “host board.” Hereinafter, a board included in a communication apparatus and with which a communication module is connected will be referred to as a “motherboard.”
For a connector connecting the communication module and the motherboard, a two-piece structure connector including a male connector (plug connector) and a female connector (receptacle connector) has been used in many cases. Further, when the two-piece structure connector is used to connect the communication module and the motherboard, the plug connector is arranged in the communication module, and the receptacle connector is arranged on the motherboard, in many cases.
The plug connector arranged in the communication module includes an insertion projection portion inserted in the receptacle connector. The insertion projection portion is provided with a plurality of connection pins connected to a plurality of connection pins provided in the receptacle connector. These connection pins are electrically connected with a board housed in a housing of the communication module. The board housed in the housing of the communication module will be referred to as a “module board” below and distinguished from the board (motherboard) of the communication apparatus.
At an end of the module board, a plurality of connection pads forming an edge connector are arranged. When the plug connector and the module board are coupled, the connection pins provided on the insertion projection portion of the plug connector contact the connection pads arranged at the end of the module board to be electrically connected.
More specifically, a plurality of upper connection pins aligned in one row and a plurality of lower connection pins aligned in one row are provided in the plug connector, and the row of the upper connection pins and the row of the lower connection pins are opposed to each other across a gap. Further, the end of the module board provided with the edge connector is inserted in a gap between the row of the upper connection pins and the row of the lower connection pins.
In this regard, the gap between the row of the upper connection pins and the row of the lower connection pins is narrower than a thickness of the module board. In other words, an opposing interval between the upper connection pin and the lower connection pin is narrower than the thickness of the module board. Hence, the end of the module board inserted in the gap between the row of the upper connection pins and the row of the lower connection pins enters deep inside the gap, pushing away the upper connection pins and the lower connection pins opposed to each other in a direction in which the upper connection pins and the lower connection pins move away from each other. As a result, when the end of the module board is inserted in the gap between the row of the upper connection pins and the row of the lower connection pins, the upper connection pins and the lower connection pins come into pressure contact with the corresponding connection pads by elastic restoring forces of the upper connection pins and the lower connection pins. (Japanese Patent Application Laid-Open Publication No. 2013-84577)